Lubricating compound



' preferable to others.

Patented Aug. 5, 1941 rrso STATES LUBRICATING COMPOUND- John M. Musselman, South Euclid, and-Herman P. Lankelma, Shaker Heights, Ohio, assignors to The Standard Oil CompanyfCleveland, Ohio,

a corporation of Ohio No Drawing. Application September 28, 1939,

Serial No. 296,971

4 Claims.

and many expedients have been suggested, among them the adding an amine to a lubricating oil in the View that the presence of the free amine in some way inhibited tendency to sludge formation. We have now found that certain complex reaction products, as described hereinafter, applied to a lubricating oil shows surprising results in improved operation of the lubricant and dura-= bility, out of line with. the behavior of the individual materials going to make up such compounds. The present invention then is concerned with such improved lubricants and their preparation.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various ways in which the principle of -the invention may be employed.

We react carbon disulphide with an amine. Using a primary or secondary amine f the aliphatic, cyclo paraifin or heterocyclic type, the respective constituents are reacted at elevated temperature, sufiicient to bring about combination. The temperatures being 100 C. or-somewhat more or less, depending upon the particular amine. If molecular proportions of the constituents be taken, uncombined excesses which dilute the product may be avoided. The amine material employed is such for example as monoamylamine, butylamine, octylamine, dimethylamine, dicyclohexylamine, dipropylamine, piperidine, tetrahydroquinoline, etc. Some amines have an advantage in cost, and some yield slightly preferable products over others, and while all may be used, as indicated, some are in practice The reaction product formed from the carbon disulphide and amine is next reacted upon with sulphur. This reaction is carried out at an elevated temperature, as for instance 100 C., and the sulphur may be in any convenient form, desirab y flour of sulphur, The

final reaction results in a product-on the order of a thiuram polysulphide,

in which R1 and R2 are hydrogen or hydrocarbon groups, and n is three or more. The reaction products are soluble in oil, and are added to an oil of lubricating viscosity in small amounts, as

for instance 0.05 to 5 per cent.

As an example: With a petroleum lubricating oil of 350 S. U. viscosity at F., there is incorporated 0.2 per cent of the reaction product of carbon disulphide with monoamylamine, reacted upon in turn with sulphur.

As another example: With a lubricating oil similarly, there is incorporated 0.2 per cent of the reaction product of carbon disulphide and piperidine, reacted upon in turn with sulphur.

*As another example: Similarly with a lubricating oil there is incorporated 0.2 per cent of the reaction product of carbon disulphide and dicyclohexylamine, reacted upon with sulphur.

In internal combustion engine runs with lubricants as thus provided, the serious viscosity change or increase which occurs with an ordinary lubricating oil and the optical density increase are controlled, and the rating of the piston condition as determined by inspection after twenty hours unit test run, is particularly improved. For instance, with a lubricant as in Example 2 above, on a standard test run of twenty hours, compared with the results of such a run on the same oil without the other ingredient as in such example, whereas the plain oil showed formation of 5 per cent sludge, an optical density increase of 1,922, and viscosity increase of 193, and a piston rating 8 (on a scale of 10, 10 being the extreme condition of carbon accumulation and wear occurring with ordinary lubricating oils), the new lubricant shows a sludge formation of only 1 per cent, optical density increase 960, viscosity increase 75, and piston rating 2. Likewise, with a similar standard run, the lubricant of Example 1 above showed a sludge formation of only 1 per cent, optical density increase 1,474, viscosity increase 99, and piston rating 5.

'Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or

the equivalent of such, be employed. We therefore particularly point out and distinctly claim as our invention:

1. A lubricant comprising an oil of lubricating viscosity and a small amount of the product of reacting carbon disulphide with dicyclohexylamine and reacting the product thereof with sulphur.

2. A lubricant comprising an oil of lubricating viscosity and a small amount of the product of reacting carbon disulphide with monoamylamine and reacting the product thereof with sulphur.

3. A lubricant comprising an oil of lubricating viscosity and a small amount of the product of reacting carbon disulphide with piperidine and reacting the product thereof with sulphur.

4. A lubricant comprising an oil of lubricating viscosity and a small amount of the product of reacting carbon disulphide with an amine capable of reacting therewith, and reacting the product thereof with sulphur, to the combining of at least three atoms 01. total sulphur.

JOHN M. MUSSELMAN. HERMAN P. LANKELMA. 

